1. Field of the Invention
The invention relates generally to grade compacting devices and, more particularly, to a rammer-type compactor having an exhaust system constructed to be positioned snuggly near the body of the compactor.
2. Description of the Related Art
Compaction is generally performed in preparation of other building processes. Commonly, freshly excavated work sights require compaction of the underlying material, be it soil or gravel, prior to the placement of building materials, such as concrete, over the soil. This compaction can be performed by any of a number of devices including rollers, plate compactors, or rammers. Rammers are a class of compaction device in which an operator can hand-guide a vertically-reciprocating plate or “shoe” over the area to be compacted. The shoe is located on a lower mass driven to reciprocate via a gear crank. The operator's handle is located on an upper mass that is vibrationally isolated from the lower mass and that supports an engine that powers the gear crank. The compact, relatively light nature of rammers, permit them to be guided even if the grade is at a substantial incline or decline. Rammers are also commonly used in trenches or the like due to their compact and generally elongated vertical shape as well as the ease of mobility of such devices in confined spaces. An operator standing in a trench can relatively easily redirect the direction of travel of the rammer with generally minimal interference from the walls of the trench.
A substantial consideration of rammer construction is protection of some of the comparatively fragile components of the rammer assembly from impacts. Commonly, such impacts cause damage due to contact with, debris which may fall from above, or adjacent building materials or structures such as exposed reinforcing rods, etc. Although some such damage may be considered generally cosmetic in nature, such as blemishes to the finish of the machine, other components of the rammer, notably the exhaust system, may be damaged during use.
Rammers are also susceptible to damage during transit. The generally upright orientation of rammers complicates the transportation of such devices. When it is impractical to transport the rammer in its normal, upright position, many users lay the rammer on its side so as to avoid undesired tipping of the rammer. Placement of the rammer in such a horizontal orientation presents an additional opportunity for damage to the comparatively fragile or deformable components of the rammer assembly.
Others have recognized the importance of protecting the lateral surfaces of rammers from damage. Unfortunately, these solutions are not without their respective drawbacks. One such device includes the positioning of multiple guards around the exhaust system and other relatively fragile components of the rammer. The guards are secured to the comparatively robust components of the engine housing and the gear case. Unfortunately, such a configuration communicates the impact loading of the guards directly to components which, if damaged, render the rammer inoperable. That is, an impact that previously would have resulted merely in “cosmetic” damage now has the potential to render the machine unusable due to fractures of either of the engine block or the crankcase.
Such guard systems also undesirably increase the volume occupied by the machine. That is, they increase the space occupied by the machine in storage, during transit, and in use. The guards also increase the weight of the machine, add to manufacturing costs, and complicate maintenance procedures. To mitigate the detrimental weight considerations, some manufactures have formed the guards out of thick-walled aluminum which in turn detrimentally increases the material costs associated with manufacturing the rammer. The guards also must be removed to replace or maintain the components protected by them. Complex fastener assemblies that secure the guards to the machine only further frustrate service efforts.
Guard systems assemblies also commonly include a number of openings to allow adequate airflow into the cavity behind the guard. The air flow is necessary for cooling of machine components and combustion. Unfortunately, the number and size of the openings has the tendency of allowing debris to pass through the guards. The holes also provide the potential for poking damage to the components positioned behind the guard. Roots or other structures may also snag on the holes.
Therefore, there is a need for a rammer that is constructed to protect the deformable systems of the rammer with consideration given to the weight of the machine and the spatial occupation of the machine.